﻿#define _CRT_SECURE_NO_WARNINGS 1

//输出空心正方形图案
#include <stdio.h>

int main() {
	int n = 0;
	int i = 0;
	int j = 0;


	while (scanf("%d", &n) != EOF)
	{
		for (i = 0; i < n; i++)
		{
			for (j = 0; j < n; j++)
			{
				if (i == 0 || i == n - 1 || j == 0 || j == n - 1)
					printf("* ");
				else
					printf("  ");

			}
			putchar('\n');
		}
	}

	return 0;
}
